Research in Developmental Disabilities
Study 3- Disambiguating the ‘balls’ condition
Paulus et al.’s (2011) ‘balls’ condition was designed so that it should be considered functionally equivalent to the ‘hands occupied’ condition of the Gergely et al (2002) as hands were occupied with balls, while as in this case the head action was demonstrated with the hands placed on the table, this hand and body configuration was perceptually similar enough to the ‘bend over with manual body support’ sort of head-touch action that the infants are able to perform. Let us, however, have a closer look on what was manifested for the infants in this demonstration condition. Again, we would like to highlight the role of ostensive communicative and temporal parsing cues that could guide infants’ inferences on what was shown for them in the situation.
In the ‘balls’ condition of Paulus et al. there were two softballs lying on the table next to the lamp,.During the demosntration, after taking a seat, the experimenter started to play with these softballs for approximately 8 seconds. The experimenter kept one softball in each hand and put her hands next to the lamp. Then, the procedure followed exactly the procedure of the ‘hands free’ condition with the only difference that the experimenter was holding the two softballs in her hands during the experiment.
In this condition also, we find ambiguous what is demonstrated: are the hands really occupied by holding the balls or are they in fact free, just resting on the balls? Remember that as part of the demonstration context, the model - just before presenting the head action - played with the balls, freely using her hands. It is possible so, that this demonstration in
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itself was enough to induce the inference, that the model could use her hands whenever she wanted, but she chose to use her head instead to light up the box.
Our attempt to disambiguate this condition was a simple modification of the demonstration condition that could help infants to parse and interpret the ongoing action: in the ’Hands free keeping balls‘ condition we followed exactly the procedure of the ‘Balls’ condition in the Paulus et al study, except that 1. the two balls were lying on two little plates next to the table, 2. and after the model put her hands next to the light-box keeping balls, she lifted up her hands without the balls for 2-3 seconds, the balls stayed in the plates, and could not roll away, then the model re-grasped them. After this short event, the model performed the head action with her hands resting on the table, keeping balls. In this context it was made explicit during the demonstration that the hands are free. In the Hands occupied with balls’ condition there was no plates next to the light-box, and the model performed the very same action sequence like in ‘Hands free keeping balls’ condition. So, when she lifted up her hands for a little, the balls could roll away, so she had to reach and stop them by re-grasping. In this situation the unavailability of the hands were unambigously manifested. In both of the situations, the model provided support for her bending forward action with her hands (keeping balls) so, according to motor resonance theory there should be no difference in the amount of imitators in the two conditions. In contrast the different situational constraints presented in ostensive communicative context could highlight for infants that the model made a contrastive choice - approving the relevance of the new head action - only in the
’Hands free keeping balls’. If this assumption is true, the amount of imitators should differ in the two conditions.
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26 Method
Participants
Thirty 14-month-old infants were recruited through advertisements in local newspapers.
Three of them were excluded from the final sample because of fussiness (n = 1), technical error (n=1), and parental inference (n=1). Participants were randomly assigned to two experimental conditions, as a result finally 14 infants were tested in hands free keeping balls condition and 13 infants were tested in the hands occupied with balls condition.
Apparatus
The apparatus and setting was identical to the apparatus introduced in Study 1. Additionally two small coloured plastic balls (diameter 5 centimeters) were used. Furthermore, in the hands free keeping balls condition there was two small white plates (diameter 9 centimeters) next to each side of the box. The sessions were monitored and videotaped.
Procedure
In this study we employed a short delay between the modeling and test phases, like in Study 1, and our conditions were all presented in ostensive-referential context.
Modeling phase. The general procedure was identical to the procedure introduced in study 1.
In the ‘Hand occupied with balls’ condition, after taking a seat, the model started to play with two little balls, throwing them up for 8-10 seconds. Then the experimenter put the balls on the table next to each side of the box. In this condition, the model invisibly let the balls roll away and just after it she re-grasped them. The model rested her hands on the table keeping the balls in her hands during the demonstration. Then the procedure followed exactly the general demonstration of the head touch: the model bent forward from waist and
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In the ‘Hands free - keeping balls’ condition, as well as in the former condition, after taking a seat, the model started to play with two little balls, throwing them up for 8-10 seconds. Then the experimenter put the balls on the table next to each side of the box.
However, in this condition there was two little plastic plates next to each side of the box, thus the experimenter placed the balls into these plates. After putting down the balls the model lifted up her hands for 2-3 seconds and grasped again the balls and kept them in the hands during the demonstration. The balls could move on the plates, but they could not roll away. Here again, the procedure followed exactly the general demonstration of the head touch: the model bent forward from waist and lit up the lamp by touching it with her forehead. Note that in both conditions the balls could roll during the short presentation of lifting up the hands, so both presentations contained equal amount of movements, and were equally salient perceptually.
Test phase. The test phase followed the modeling phase immediately in both conditions. The model pushed the lamp across the table in front of the infants, and told ‘It is your turn now!
You can try it!’ She encouraged the infant to play with it and stayed in the room. Infants were given 60 seconds to play with and explore the lamp.
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28 Data analysis and scoring
The video records of the test phase were scored by two independent observers who were uninformed as to which of the conditions the participant belonged to. The dependent measure was whether the infant attempted to perform the head-on-box action within a 60 s time window (like in study 1). The two coders' evaluation of the participants' performance was in 92 % agreement (Kappa = 0.85).
Results
Number and proportion of infants who performed the target action are presented in Table 2.
--- Please insert Table 2. here.
---
We compared the performance in the two conditions to each other and it was revealed that the frequency of target action was lower in the ‘Hand occupied with balls’ condition than it was in the ‘Hands free keeping balls’ condition (Fisher exact p = .054).; Odd ratio
(OR=5,177) examination revealed that the probability of performing a head touch is more likely in the ‘Hands free keeping balls’ than in the ‘Hand occupied with balls’ condition.
Hand actions preceded head action in 94 % of cases. The frequency of hand actions was almost 6 hand action for a head touch Moreover, like in study 1, the head touches did not follow the modeled head touch with high fidelity: intriguingly, in 50 % of the cases infants lifted up the lamp to their heads instead of leaning forward to it (4 infants in the Hands Free keeping balls condition and 2 infants in the Hands Occupied with balls
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performed the head action this way). Also in 58 % of cases (out of which 25 % - 3 infants were lifters) there was no contact between the approaching head and the lamp.
Discussion
With a simple modification to the ‘balls’ condition of Paulus et al., we made the situation unambiguous whether the hands are really occupied with another, parallel action (Hands occupied with balls’ condition), or the hands are really free, continuously available (‘Hands free keeping balls’ condition). Given that infants were presented with different constraints, these situations are similar to the original structure of the ‘hands-free’ and ‘hands-occupied’
conditions of Gergely et al. (2002), but the motor behavior performed in the two contrastive conditions are identical. We found that in the ‘Hands free keeping balls’ condition infants tended to imitate the target new behavior, 65 % of infants re-enacted the head action, replicating the results of Paulus et al (and also the original results of ‘hands-free’ condition of Gergely et al., 2002). In contrast, in the ‘Hands occupied with balls’ condition only 23 % of infants imitated the target action, (replicating the results of the ‘hands occupied’ condition of Gergely et al., 2002). Since the motor behavior was identical in the two conditions, motor resonance account (or any low-level approaches based on perceptual dissimilarities) could not explain the different pattern of re-enactment, and thus these results bring to light the role of inferential processes beneath imitation.
General Discussion
The main objective of the present paper was to provide a fair empirical contrast for the motor resonance and the relevance based account for the phenomena of selecive imitation with the help of situations in which demonstration cues were available to help infants in interpreting the target behavior while behavioral, motor components were kept contstant.
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Our studies revealed selective imitative patterns as a function of different demonstration contexts despite the fact that the modeled target behaviors and related components were very similar or identical in our conditions. These findings challenge the interpretations of motor resonance or automatic direct matching processes since these approaches cannot grasp the influence of contextual cues on imitative patterns in case of similar modeled actions. Indeed, these result speak for the supposition of inferences induced by contextual cues that guide imitation in infants.
Our supposed interpretation of inference based selective imitation is that infants do not automatically produce a matching motor program (with high fidelity) but they encode the goal of the situation and they retrieve a behavior that is effective in its attainment. In addition, it is proposed that natrural pedagogy modulates what is learnt in the situation (Gergely,& Csibra, 2005, 2009, Király, Csibra and Gergely, 2013): communication can enrich the encoding of the goal with signaling the particular means (or features of it) as a culturally relevant way to goal-attainement that is manifested as worth-to be learnt.
The findings , hence, promote the refinement of the previous theoretical position of rational imitation (in accordance with the objections of Paulus, 2012201). Paulus (2012), analyzing the theory of rational action (Gergely & Csibra, 2003) and the proposal that infants engage in rational imitation (Gergely et al., 2002), has argued that this theory is based on several assumptions, such as that infants are able to evaluate others’ action capabilities, that they possess conceptual body representations, and that infants engage in counterfactual
reasoning. Yet, Paulus suggests that there is no evidence that these abilities are in place in young infants. Furthermore, applying Hacker’s (2010) considerations, he has criticized the introduction of a cognitive principle as an explanation of human behavior as being a theoretical fallacy.
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Our refined account could answer the criticism on the original rational imitation account put forward by Paulus (2012). In our novel account it is underlined similarly to the second point of Paulus (2012) that the problem with the original assumption (Gergely et al, 2002) is that it attributed the operation of the exact same inferential principle behind different (opposite) behavioral patterns. Namely, in our view the main problem with the original proposal as it stands was that it essentially made the idea of appealing to the rationality principle un-falsifiable: When infants did not reproduce the demonstrated action (in the 'hands occupied' condition), it was treated as evidence of the application of the rationality principle, and when they did reproduce it (in the 'hands free' condition), it was also interpreted as evidence for the operation of the same inferential principle (cf. Gergely and Jacob, 2012). The refined model we argue for in the present paper elaborates the role of inferential processes beyond action analysis, and argues that ostensive communication enables infants to represent the goal structure (overall goal and subgoal of specific means) of novel actions even when the causal relations between means and end are cognitively opaque.
It is proposed that the presumption of relevance guides the interpretation of the
demonstration by searching for a communicative content that appears in some way relevant to the recipient. It is still suggested that the principle of efficiency is employed, to compute and disregard action elements of the observed demonstration that are justifiable by situation-specific physical constraints. So this refined theory of teleological explanation of selective imitation suggest that infants do not have to engage in counterfactual reasoning, (neither do they have to be able to evaluate others’ action capabilities, and they do not have to possess conceptual body representations): we suggest that after the observation of a novel goal-directed action, (1) infants can identify the goal (otcome) of the action that they encode; (2) when they invited to re-enact, young children recall the encoded goal (or goals / otcomes), and (re-)enact to attain the same goal-state. Most importantly, they turn to encode the novel
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means as a subgoal when it is signaled as novel information in ostensive communicative context.
In our view, to provide an adequate explanatory model of the role of imitative re-enactment in human cultural learning, any viable theory must be able to account for two significant empirical properties of the way human infants acquire novel skills from observing them performed by others in their social environment. The first problem is how to account for the remarkable species-unique ability that makes even pre-verbal infants capable of fast-learning, long-term retention and delayed (but functionally appropriate) re-enactment of novel means actions observed even in cases when the new functional skill had been presented to them only on a single occasion and it’s re-enactment takes place a week (or, even months) later (as demonstrated e.g. by Meltzoff’s, 1988, 1995).
Second, it is crucial to account for (let alone predict) the adaptive ability of human infants (and more widely, of ‘human cultural novices’) to flexibly but appropriately generalize and selectively reproduce the newly acquired motor skill across a variety of functionally
relevant novel contexts. The proposed inference-based account can provide solutions for the above two problems, since 1) infants exhibit in our study as well that they encoded a novel behavior after only several demontrations; further more 2) a recent study using a similar head- touch props provided evidence on functionally appropriate generalization of the
‘head-touch’ action across different person-contexts as well as to across featurally clearly different new token items belonging to the artifact kind ( see Chen et al., (2012). These problems, however, represent challenges for motor resonance accounts.
In sum, our results argue for the claim that re-enactment in the observer is achieved not by direct matching but by emulative action reconstruction process. It is important to emphasize, that though we refer to ‘imitation’ (underlining the fact that infants tend to follow a new means-action), this term is used in a broad sense: a closer look at the concrete
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form of re-enacted target actions uncovered that the means were used in a flexible manner.
Infants did not always bend forward and contacted the lamp with their forehead, rather they either lifted the lamp up or bend forward to approach the lamp with the head. Moreover, in lots of cases (30 % in Study 1 and 58 % in Study 2, respectively) infants did not bring about the outcome but they ‘reinstated’ the observed goal. Hence, the main findings of the
presented studies supports the view that action understanding and goal inferences rather precede, than follow from, action mirroring processes (Csibra, 2007).
Acknowledgement:
This research was supported by an OTKA K 109352 research grant to Ildikó Király. The European Union and the European Social Fund have provided financial support to the project under the Grant agreement TÁMOP 4.2.1/B-09/1/KMR-2010-0003. The authors thank the infants and their parents for their participation; and Erna Halász, Eszter Somogyi and Leila Preisz for running the experiments.
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